The disclosure generally relates to a driver circuit and, more particularly, to a driver circuit for improving luminous efficacy of a LED device and related constant current regulators.
Many traditional luminance devices that utilize LED devices as a light source drive the LED devices by using electricity from AC power source. Therefore, an electrolytic capacitor is typically arranged in a voltage input path in order to improve the luminous efficacy of the LED devices. The durable time of the electrolytic capacitor, however, is typically shorter than that of the LED devices. Once the electrolytic capacitor malfunctions, the traditional luminance device is unable to operate normally. Apparently, the use of the electrolytic capacitor in the luminance device not only causes adverse influence to a power factor of the luminance device, but also reduces reliability and durable time of the luminance device.